Magneto ignition system for internal-combustion engines.



l. L. MILTON. MAGNETO IGNITION SYSTEM FOR INTERNAL COMBUSTION ENGINES.

APPLICATION HLED MAR. 1a. 1911.

1 217,484. Patented Feb. 27, 1917.

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MAGNETO IGNITION SYSTEM FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED MAR. I8, 1911.

1,217,484. Patented Feb. 27, 1917.

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MAGNETO iGNlTlON SYSTEM FOR INTERNAL COMBUSTLON ENGINES.

APPLICATION r1120 MAR. 18. 1911.

1,217,484. Patented Feb. 27, 1917.

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APPLICATION FILED MAR. I8, I911.

Patented Feb. 27,1917.

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UNITED STATES PATENT omuon JOHN LEWIS MILTON, OF TIFFIN, OHIO, ASSIGNORT0 MOTOR IGNITION & DEVICES COMPANY, A CORPORATION OF WEST VIRGINIA.

MAGNETO'IGNITION SYSTEM FOR INTERNAL-COMBUSTION ENGINES.

Specificatidn of Letters Patent.

Patented Feb. 27, 1917.

To aZZ whom it may concern:

Be it known that 1, JOHN L. MILTON, acitizen of the United States,residing at Tifiin, in the county of Seneca and State of Ohio, haveinvented a certain new and Improved Magnet-o Ignition System forInternal-Combustion Engines, of which the following is a full, clear,concise, and exact description, reference being had to the accompanyingdrawings, forming a part of this specification.

My invention relates to magneto ignition systems for internal combustionengines and its object is to provide means for producinga spark whichwill be hotter and larger than the sparks produced by thesystemsheretofore known and commonly used, without involving the use ofmore apparatus and without incurring prohibitive expense.

An instance of my invention is illustrated in the accompanying drawings,in which Figure 1 is a diagrammatic representation of the circuit;

Fig. 2 is an end elevational View of the magneto machine which might beemployed;

Fig. 3 is a view similar to Fig. 2 with the cover plates removed so asto reveal the construction of the timer and the distributer;

Fig. 4 is a vertical axial sectional View of the generator and thedistributor and timer carried thereby; and

Fig. 5 is a detail view showing a mecliani cal embodiment of the specialspark gap termina-ls referred to.

Like reference characters are applied to the same parts throughout thevarious fig- Referring first to Fig. 1, it will that the current issupplied by means of a generator G which is provided with the rotatablecore R and the armature coil W wound thereon. One terminal of thewindfour-cylinder engine and in one instance I be seen I have shown astructural embodiment of the spark plug. The current generated by thegenerator G is a low-tension current and in order that a high-tensioncurrent mav be supplied to the main spark gap terminals 8, s, I providea transformer coil C, comprising a primary winding P and the secondarywinding S, which is of such construction that it may withstandconsiderable heat and may therefore be mounted, by means of a. bracketB, directly on the spark plug. \Vhen the transforming means is thus soclosely associated with the spark plug the considerably greater part ofthe circuit is required to carry merely a low-tension current. Thistransformer is preferably coreless and the primary winding is disposedoutside the secondary winding. The primary winding comprises 12'} turnsof No. 20 copper wire and the secondary winding comprises 850 turns ofNo. 30 copper wire. The

terminal T is common to both windings and the terminal T forms the otherterminal of the primary winding, while the bolt M forms the otherterminal of the secondary winding. The bolt M is connected by means of aclip N with the conducting post passing through an insulating sleeve inthe spark plug and terminating in one of the terminals of the associatedspark gap.

Each of the transformer coils has the terminal which is common to boththe primary and secondary windings connected with a respective contactof the distributor. The other terminal of the secondary winding, asbefore stated, is'connected with one of the terminals of the spark gapwhile the other terminal of the spark gap is grounded, as indicated. Theother terminal of each primary winding is connected to a conductor .gwhich leads to the stationary contact h of the timing device. Thistiming device is provided with the movable contact k which is subjectedto the action of a rotary cam 0 and is grounded as indicated in thedrawing.

The timing device is shunted by a branch circuit which includes acondenser E and a special spark gap X, this spark gap being adjustableso that the most effective size may be secured. The condenser E ispreferably about 2 inches wide by 3 inches long and comprises about 8sheets of tin insulated from each'other by means of split mica. A

' surrounding the bearing 13.

condenser F is connected in bridge of the generator winding. Thiscondenser is of about the same construction as the condenser E exceptthat it comprises about 12 sheets of tin.

The magneto machine which I have illustrated diagrammatically at G inFig. 1 and which is shown in some detail in Figs. 2, 3 and 4 is a modelD Splitdorf Standard machine except that the distributer has beenmodified somewhat. T have tried this magneto in connection with thesystem illustrated in Fig. 1 and hereinbefore described and, findingthat excellent results were obtained, it make mention of a specific formwhich T have employed and of the sizes of wire and sizes of condensers,in order that those skilled in the art may be fully informed.

The illustrations, Figs. 2, 3 and 4, are full size and are drawnsubstantially to scale. The pole frame is indicated at 6 and the fourhorseshoe magnets which are associated therewith are shown at 6, 6. Onone side the pole frame is provided with an end plate 7 which is securedthereto and to the adjacent magnets in any suitable manner and whichprovides the bearings for the armature shaft and the distributer shaftas will be pointed out presently. On the other side the pole frame isprovided with a small end plate 8 which is secured thereto in anysuitable manner. The armature is illustrated at 9 and is mounted upontrunnions 10 and 11 which are journaled in suitable bearings 12 and 13in the respective side plates. The trunnion 10 is adapted for thereception of a gear or belt wheel by way of which it may be driven. Thearmature winding is illustrated at W. One terminal thereof is groundedto the machine and the other is connected by means of a rod 15,extending through the trunnion 11 but insulated therefrom by means of asleeve 16 with brushes 17. 17 which make electrical connection with theinside of a stationary cup 18. This cup carries the binding terminal 19which will be referred to later.

The trunnion 11, where it extends beyond its bearing, is provided withor is formed into a cam 0 with which is associated a follower roller 21mounted upon a follower arm 71: pivoted at 23 to a cup structure 24which'is slipped on over the circular wall A helical spring 25 tends tohold the follower down upon the cam and a leaf spring 26, secured to theinside of the cup, assists in this behalf. The follower arm in forms themovable member of the timing device and the stationary member [L whichis carried by but insulated from the cup, is associated therewith. Thisstationary member is in the form of a screw, which may be set in anyadjusted position, mounted in asupporting 'must be geared to piece 28secured to the cup by means of a bolt 29 but insulated therefrom bymeans of insulation 30. A binding post 31 is supported with the piece 28and is electrically insulated with the stationary contact. The bindingpost 32 affords means for securing a conductor to the magneto frame andin this way electrical connection to one terminal of the armaturewinding and to the movilllle member of the timing device may be lad.

The trunnion 11 carries a pinion 33 which meshes with a gear 34 carriedupon a shaft 35 mounted in bearings 36, 36 set in aboss 37 on the endplate 7. This gear carries the insulating block 37 upon which is mounteda conducting plate 38 and the wiping contact springs A, A. An insulatingcover 40 is secured over the gear and the insulating block carriedthereby and this cover carries the four contacts a, b, c and (Z whichare so disposed asto be equidistant from the axis of the gear. Thewiping springs A, A are so positioned that as they revolve they mayengage with the four contacts and in this way the distribution of thecurrent to .the various cylinders of the associated combustion engine issecured. The insulating cover 4( is provided with an axial plug 41 whichis provided with a central socket 42 in which a plunger brush 43 isconfined against the tension of a coiled spring. This plunger brushmakes contact with the member 38 and consequently is electricallyconnected with the wipers A, A. A connector 43 connects the binding post19 with the plug 41 and in this way one terminal of the armature windingis connected with the rotatable member of the distributer.

. A mechanical embodiment spark gap X is illustrated in Fig. 5. It isconvenient to mount two conducting plates 44, 45 upon an insulatingblock 46 which may be secured to the side of the magneto machine bymeans of a screw 47. The conducting plates 44 and 45 are provided withlugs 48 and 49 respectively and each of these lugs is provided with acontact terminal member 50. One or both The condensers E and F are shownas disposed together within the horse-,

shoe magnets.

Since spark plugs are provided for a fourcylinder engine, thedistributer brush A the armature of the generator m a two to one ratioso that the armature may make two complete revolutions during a singlerevolution of the brush. As-

suming the distributer blade to be in electrical connection with any oneof the contacts of the distributer it will be seen that the current wavegenerated upon rotation of the armature may be traced from one terminalof the winding W to the distributer brush A, thence through thedistributer contact I), thence through the primary winding P of theassociated transformer coil, thence through the conductor 9 to thestationary contact of the timing device or interrupter, and then throughthe movable member In W thereof and back to the other terminal of thewinding WV. The cam mechanism is timed to open the interrupter contactsslowly when the spark is to be produced in the engine cylinder. Thetiming is arranged so that these contacts will be opened at orreasonably near the peak of the current wave set up in the generator. Ido know that a tremendously hot and powerful spark is caused to jumpbetween the spark contacts of the plug and apparently at the same time avery small spark jumps between the contacts of the spark gap X. Thedistance between the contacts of the gap X is preferably small. Althoughthe exact pathspf the primary and secondary currents may not bedeterminable with absolute certainty, I find that when the circuitbreaker is opened,

either one or both of the condensers disruptively discharges across thefixed spark gap and through the primary of one of the coils, so that ahigh frequency current traverses the primary, causing a high frequencycurrent of higher voltage to be induced in the secondary and to jump thegap of the corresponding spark plug, and causing a relatively lowvoltage, high amperage current from the magneto or source to follow theare which is produced at the plug by the induced high frequency current,resulting in a flaming arc of high heat value. It is to be noted that aseach transformer coil is coreless, the fixed spark gap and one or bothof the condensers and the primary of a coil are in a series circuit oflow,impedance so that the condenser or condensers may disruptivelydischarge therethrough;

Additionally, it should be noted that the secondary of the coil andspark slug are likewise in a circuit of low impe ance so that they maybe traversed by the induced high frequency current, and as this circuitincluding the secondary and plug, is connected by the distributerdirectly to the magneto, current from the source may readily flow acrossthe gap of the plug when its resistance is reduced by the inducedhighfrequency current. The sparking between the contacts h and 1c isvery slight.

' It might be well to mention in connection with the other details thatthe transformer coils C of this system are of the kind described in mycopending application, Serial No. 591,930, filed November 12, 1910. Theyare about 2?; inches in diameter and about 5 of an inch in thickness.

\Vhat I claim as new and desire to secure by Letters Patent is:

1. In combination in an ignition system, a source of current, a sparkplug, a primary coil, a secondary coil, a condenser connected to thesource, a fixed spark gap, said condenser, spark gap and primary coilbeing in a circuit of low impedance, and said secondary and spark plugbeing in a circuit and having a connection with the source.

2. In combination in an ignition system, a source of current, a sparkplug, a primary coil, a secondary coil, a condenser connected to thesource, a fixed spark gap, said condenser, spark gap and primary coilbeing in a circuit through which the condenser may discharge, saidsecondary coil and spark plug being in a circuit and having a connectionwith the source, and a circuit breaker connected to the source andadapted to open a) and close a circult including the latter.

3. In combination in an ignition system, a source of current, a sparkplug, a primary coil, a secondary coil, a condenser connected to thesource, a fixed spark gap, said condenser, spark gap and primary coilbeing in a circuit through which the condensermay discharge, saidsecondary coil and'spark plug being in a circuit and having a connectionwith the source, and a circuit breaker adapted toopen and close acircuit including the source,-said spark gap and condenser being inshunt to the circuit breaker.

4. In combination in an ignition system, a source of current, a sparkplug, a primary coil, a secondary coil, a condenser connected to thesource, a fixed spark gap, said condenser, spark gap and primary coilbeing in a circuit of low impedance, said secondary coil and spark plugbeing in a circuit and having a connection with the source, and asecondcondenser connected between the terminals of the source.

5. In combination in an. ignition system, a source of current, a sparkplug, a primary coil,'a secondary coil, a condenser connected to thesource, a fixed spark gap, said condenser, spark gap and primary coilbeing in a circuit through-which the condenser .may' discharge, saidsecondary coil and Fits a condenser connected to the source and adaptedto be disruptively discharged, a fixed spark gap, a highfrequency coilincluding a primary connected in series relation with the condenser andspark gap, and a secondary in series relation with the spark plug.

7. In an ignition system, in combination with a spark plug, means forproducing at the spark plug a high frequency are followed by a hot lowtension arc comprising a source of current connected to the plug, acondenser connected to the source and adapted to be disruptivelydischarged, a fixed spark gap, a high frequency coil including a primaryconnected in series relation with the condenser and spark gap, and asecondary in series relation with the spark plug, and a circuit breakerfor opening and closing a circuit including the source.

8. In an ignition system, in combination with a spark plug, means forproducing at the spark plug a high frequency are followed by a hot lowtension arc comprising a source of current connected to the plug, acondenser connected to the source and adapted to be disruptivelydischarged, a fixed spark gap, a high frequency coil including a primaryconnected in series relation with the condenser and spark gap, and asecondary in series relation With the spark plug, and a circuit breakerfor opening and closing a circuit including the source, said condenserbeing connected in shunt to the circuit breaker.

ted to be disruptively discharged, a

9. In an ignition system, in combination with a spark plug, means forthe spark plug a high frequency are followed by a hot low tension arecomprising a source of current connected to the plug, a condenserconnected to the source and adapted to be disruptively discharged, afixed spark gap, a high frequency coil in cluding a primary connected inseries relaand spark gap, and

producing at tion with the condenser a secondary in series relation withthe spark plug, and a circuit breaker for opening and closing a circuitincluding the source, said condenser and spark gap being in shunt to thecircuit breaker.

10. In an ignition system, in combination with a spark plug, means forproducing at the spark plug a high frequency are followed by a hot lowtension arc comprising, a source of currentconnected to the plug, acondenser connected to the source and adaptfixed spark gap, a highfrequency'coil including a primary connected in series relation with thecondenser and spark gap, and a second ary in series relation With thespark plug, and a second condenser connected across the terminals of thesource.

In witness whereof, I hereunto subscribe my name this 14 day of March,1911.

JOHN LEIVIS MILTON.

Witnesses:

ALEX. KISKADDIN, EUGENIA K. ADAMS.

